Musculoskeletal disorders are a major public health problem in most parts of the world, yet relatively few studies have been undertaken of the epidemiology of most of these conditions. Furthermore, there have been few review articles written on epidemiologic aspects of individual disorders, let alone of all the major musculoskeletal conditions. This book brings together and critically analyzes the relevant literature on the epidemiology of the major musculoskeletal disorders. Although the text was written by an epidemiologist primarily for epidemiologists and other public health practitioners, many of whom have little knowledge of the disease processes involved, it is hoped that orthopedists, rheumatologists, and other physicians will skip over the simplified descriptions of the diseases and find the epidemiologic material instructive and enlightening. There is a certain unevenness in the quantity and quality of the material presented on the different diseases.^ In part, this may reflect the author's more extensive experience in some areas than in others and to her greater depth of knowledge of some diseases than others. However, there is also tremendous variation in the amount of information available on the epidemiology of the various diseases, and while a few diseases have been studied fairly extensively, no epidemiologic studies have been undertaken of many of them. Accordingly, throughout the book many preliminary findings are presented that are in need of further study. It is hoped that readers will note the many gaps in the understanding of the epidemiology of these diseases and will recognize the areas in which further study is needed. One important service this book could perform would be as an impetus for other investigators to undertake their own studies to enhance our understanding of the epidemiology of musculoskeletal disorders.^ In light of the high frequency of these conditions in the population, any new information that could be used to prevent their occurrence or to reduce their impact would certainly be of benefit to society.